Silver halide emulsion containing purple coupler for color photography and process of making the same

ABSTRACT

A PURPLE COLOR COUPLER HAS THE FORMULA   1-(R1-C6H4-),3-(R2-OOC-NH-C6H4-NH-),4-R3,5-(O=)-2-   PYRAZOLINE   WHEREIN R1 IS HYDROGEN OR ONE OF THE SUBSTITUENTS USUALLY EMPLOYED WITH 1-PHENYL-PYRAZOLONES; R2 IS ALKYL, CYCLOALKYL, ARYL OR ARYLOXYALKYL OR ONE OF THESE GROUPS WHICH IS SUBSTITUTED AS CUSTOMARY IN PYRAZOLONE COUPLERS; R3 IS HYDROGEN OR A SUBSTITUENT AS CUSTOMARY IN PYRAZOLONE COUPLERS WHICH, UPON COLOR DEVELOPMENT, IS SPLIT OFF; AND WHEREIN AT LEAST ONE OF R1 AND R2 IS OR INCLUDES AN ANTIFUSION STRAIGHT-CHAIN OR BRANCHED HYDROCARBON GROUP HAVING FROM 8 TO 20 CARBON ATOMS.

United States Patent Ofice 3,677,764 Patented July 18, 1972 3,677,764 SILVER HALIDE EMULSION CONTAINING PURPLE COUPLER FOR COLOR PHOTOG- RAPHY AND PROCESS OF MAKING THE SAME Hans Glockner, Pullach, Ernst Meier, Munich, and

Walter Puschel, Leverkusen, Germany, assignor to Agfa- Gevaert Aktiengesellschaft, Leverkusen, Germany No Drawing. Filed Aug. 12, 1969, Ser. No. 849,498 Claims priority, application Germany, Aug. 14, 1968, P 17 97 083.1 Int. Cl. G03c 1/40 US. Cl. 96-100 13 Claims ABSTRACT OF THE DISCLOSURE A purple color coupler has the formula DIIH C=O O O N wherein R is hydrogen or one of the substituents usually employed with l-phenyl-pyrazolones; R is alkyl, cycloalkyl, aryl or aryloxyalkyl or one of these groups which is substituted as customary in pyrazolone couplers; R is hydrogen or a substituent as customary in pyrazolone couplers which, upon color development, is split ofi; and wherein at least one of R and R is or includes an antifusion straight-chain or branched hydrocarbon group having from 8 to 20 carbon atoms.

BACKGROUND OF THE INVENTION The invention relates to a diffusion-proof color coupler which is based on the principle of chromogenic develop ment and adapted to react with the oxidation product of developers of the p-phenylenediamine type to give purple color images. This type of purple coupler is used in practical applications in one of the three layers of a multilayer photographic color material. The other two layers include the color couplers for the yellow and the blue-green image portion.

The usual purple couplers for multilayer color materials are derivatives of pyrazolones. Particularly useful have proven in this connection the acylaminoanilinopyrazolones of the formula NH (50 N I I wherein:

R is hydrogen or one of the customary substituents in this type of pyrazolone compound R is alkyl, aryl or one of these compounds which likewise is substituted as indicated for R and R is hydrogen or a phenylazo group.

This type of coupler has for instance been disclosed in US. Pats. 2,983,608 and 3,127,269 and in the Japanese Pat. 6,031/65.

This type of color component, however, can be produced only with difiiculty in pure form. For instance, in case of acylation in acetonitrile, it is necessary to boil the amino-anilinopyrazolone with the acyl chloride for several hours. In this process darkly colored by-products are formed which cannot easily be separated.

In case of acylation in pyridine or dimethylaniline a poor yield is obtained and, besides, decomposition products also occur in this process.

In case of acylation by the so-called phosphorazo method, there are likewise rather large fractions of darkly colored by-products obtained.

Because of these shortcomings in the manufacture, the application of acylamino-anilinopyrazolones in industrial practice is rather limited.

Therefore, it is an object of the present invention to provide for a purple coupler of the general amino-anilinepyrazolone type which can be produced Without incurring any of the difiiculties indicated. It is a further object of the invention to provide for a process of making this type of coupler without the shortcomings of the prior-art processes.

SUMMARY OF THE INVENTION These objects in brief are met by forming aminoanilinopyrazolones wherein, instead of the COR group a COOR group is provided.

More specifically, the new couplers of the invention have the formula NH =0 60 2 l I R: RI

wherein R is hydrogen, alkyl, halogen or an acid group;

R is alkyl, cycloalkyl, aryl, aryloxyalkyl or a substituted alkyl, cycloalkyl, aryl or aryloxyalkyl group; and R is hydrogen, halogen, an acid group or a phenylazo group or another group adapted to be split off during the color development;

and wherein at least one of R and R is or includes an anti-ditfusion straight-chain or branched hydrocarbon group having from 8 to 20 carbon atoms.

The invention also embraces a process for making the above compounds comprising reacting a chloroformic acid ester wherein the ester moiety includes an 8 to 20 carbon alkyl group with a 3-amino anilino-pyrazolone (5). The alkyl group is incorporated in the formic acid ester by reacting a correspondingly substituted alkanol or an aryloxyalkyl compound with phosgene.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The color couplers of the invention are derivatives of carbamic acid. They are preferably made by reacting an amino anilino pyrazolone with a chloroformic acid ester. As distinguished from the reaction between amino anilino-pyrazolones with normal acid chlorides, the reaction with the chloroformic acid ester proceeds many times more rapidly. This prevents the formation of undesirable by-products and, at the same time, increases the yield in the desired final product.

Examples of suitable esters of the chloroformic acid are for instance the following: ethylester, 2-hexylnonyle'ster, hexadecylester, 4-bromobutylester; cyclohexylester, tetrahydrofurfurylester; phenylester, p-nitrophenylester, p-dodecylphenylester, n-pentadecylphenylester, 2,4-dichloro-6- tetradecylphenylester, o-octadecyloxy-phenylester, p-chloro-o-tetradecylphenylester; p-butylphenoxyethylester, 2- buty1-4-nonylphenylester, m-pentadecylphenoxyethylester, p-dodecyloxyphenoxypropylester, 4 chloro 3 methyl-6- tetradecylphenoxypropylester.

The making of this type of ester has been described in the literature. It is also disclosed in German Pat. 1,176,479.

In the above formula of the compounds of the invention R is preferably chlorine or a sulfonic acid group. Preferably, there should be three chlorine atoms attached to the phenyl radical shown in the formula. R preferably is chlorophenyl or alkyl. If R is alkyl, then the alkyl group may be the anti-diffusion long-chain hydrocarbon group. If R; is chlorophenyl, then the long-chain hydrocarbon group may be substituted in the phenyl radical. [R may also be alkylphenoxy wherein the phenoxy group is attached to the main molecule by instance an ethyl group which connects the oxygen of the acid group with a phenyLa-ttached oxygen. In that case, the long-chain hydrocarbon group may again be substituted in the phenyl radical.

R may be halogen or a sulfonic acid group. In one specific type of the compounds of the invention used as masking couplers a phenylazo group is attached to the main molecule as R Groups of the following formulae, e.g., may be present:

so as to form a yellow color masking coupler.

The process of making the compounds of the invention has decided advantages compared with the prior-art acylamino anilino pyrazolone couplers.

The introduction of the anti-diffusion residue in the 3- position of the pyrazolone can easily be effected by introducing a long-chain hydrocarbon group in various manners. While in synthesizing the prior-art acylamino anilino-pyrazolones it is necessary to form the long-chain acid chlorides, it is possible with the compounds of the invention simply to react a long-chain alcohol or alkylphenol with phosgene so as to form the corresponding chloroformic acid ester. This advantage is also retained in case of the introduction of the aryloxyalkyl residue as the group R which is a preferred form of the invention.

The couplers of the invention can be incorporated in conventional manner in a green sensitive emulsion layer of a multilayer color material. If acid groups such as SO H or COOH are present in the coupler, the coupler compounds can be incorporated in the form of an alkali salt in an aqueous or aqueous-alcoholic solution. Waterinsoluble compounds of the type of the invention can be dispersed in conventional manner, for instance by use of an acetic acid ester and a wetting agent and can be incorporated into the emulsion in form of the dispersion. If a critical situation arises in this process because the color component has a tendency to recrystallize in the dispersion, it is advisable to add an oil-forming compound such as dibutylphthalate. Because of the general property of excellent dispersibility, a small amount of this addition is usually sufiicient, for instance one-half part of oil-forming agent for each part of the color component. The color compounds can be incorporated both for the negative/positive process as well as for the reversal process.

Insofar as the stability of the compounds of the invention is concerned regarding loss of sensitivity in case of storing of the emulsion layers and regarding light sensitivity of the developed color materials, the new compounds are at least equivalent to the prior-art acylamino anilino-pyrazolones if not superior. The coupling activity of the compounds is excellent with the conventional developer substances. Likewise, the absorption properties of the color materials that are formed by developing with conventional developers are excellent. This is true in particular in view of the low blue absorption.

The compounds of the invention as already indicated are of particular interest when used in the form of the 4- phenylazo derivatives as masking couplers for elimination of the blue absorption of purple color materials as has been described first in the US. Pat. 2,449,966. In many cases this type of azo masking compound effects only an incomplete coupling. As distinguished, the compounds of the invention permit obtaining of a complete coupling conversion. Noticeable is also the high stability of the masking dyes towards the bleaching bath. Noteworthy is also that after the coupling conversion the desirable properties of the parent couplers, that is the purple dyes, become dominant.

The following examples will further illustrate the invention:

EXAMPLE 1 This example illustrates a purple coupler of the formula l @Culfln Cl. 1 l 1 Stage l.4 chloro-2-tetradecylphenol 460 g. of p-chlorophenol were melted down and 7 g. of boron trifluoride was then introduced at 55 C. 196 g. l-tetradecene were then added dropwise and while stirring during a period of 2 hours. Stirring was continued for another hour, and the mass was then poured into a mixture of 1 liter water and 0.5 liter sodium hydroxide and subjected to thorough stirring for five minutes. After the phases had become separated, the oil layer was taken up in 500 m1. benzene and several times washed neutral with dilute hydroxide and water. After evaporation of the henzene, the residue was subjected to distillation in vacuum.

BJP. (0.05 mm.) ISO-158 0.; yield: 220 g.

Stage 2.4-chloro-2-tetradecylphenylchloroformate 160 g. of phosgene were introduced during a period of 40 minutes in 1.2 liter of dry toluene. A mixture of 406 g. of the phenol obtained in Stage 1, 151 g. of dirnethylene aniline and 300 ml. toluene were then added dropwise during a period of 3 hours. After standing overnight, 800 ml. of ice water was added and air was long enough blown through the mixture to remove excess phosgene. The toluene solution was then separated and washed neutral with dilute HCl and water. The chloroformic acid ester was then obtained by distilling otf the toluene in a degree of purity. The yield was 415 g.

Stage 3.-Purple component The starting product in this case was 1-(2,4,6-trichlorophenyD-B-(4"-aminoanilino)pyrazolone-(5) which has been described in US. Pat. 2,983,608. 7.4 g. of this material were dissolved while stirring in 35 mi. pyridine and then reacted at 20 C. with 8 g. of the chloroformic acid ester obtained in Stage 2. The temperature during this step rose to 40 C. Stirring was continued for 40 minutes without application of heat. The mass was then poured into a mixture of 50 m1. of concentrated hydrochloric acid, 80 ml. methanol and 80 ml. ethylacetate and was stirred for 5 minutes. After adding ml. water, the ethylacetate layer was separated and shaken out with dilute hydrochloric acid and water. The solvent was removed by evaporation and the oily residue was taken up in petroleum ether. The residue that precipitated after standing in the ice box was removed by suction and washed with petroleum ether.

M.P. 8890 C.; yield 10 g.

PREPARING A DISPERSION OF THE COUPLING COMPOUND 2 g. of the coupling compound dissolved in 3 ml. ethylacetate were dispersed in 16 ml. of a 5% gelatin solution which contained as wetting agent dodecylbenzene sulfonic acid sodium.

The dispersion was incorporated in conventional manner in a halogen silver emulsion, was cast on a support and was exposed photographically after drying and subjected to the reversal process. The color developer was 2-amino-5-diethylaminotoluene.

There was obtained a brilliant, clear, positive purple image. Absorption maximum of the dye: 541 mu.

EXAMPLE 2 This example relates to a color coupler of the formula:

-w it do HWCWOC O.NH \N Stage 1.-fi-(3-nitroanilino) -,3-methyl-rnercapto-acrylic acid ethylester 192 g. of 5,;8-dimethylmercaptoacrylic acid ethyl ester (see Laakso Suomen Kern. 17 B (1944), 2-3; (GA 1946, 4671)), 140 g. of m-nitroaniline and 0.5 g. of p-toluenesulfonic acid were heated while stirring to 130 C. Strong mercaptan separation occurred. The reaction was complete after 30 minutes. The resulting oil contained about 70% of the desired compound. Crude yield: about 230 g.

Stage -2. 1-(m-sulfophenyl)-4-(m'-nitro aniline)- pyrazolone- (5 53.6 g. of phenylhydrazine-m-sulfonic acid were suspended in 200 ml. water and neutralized with 70 g. of sodium carbonate. To the solution thus formed a mixture of 115 g. of the crude product from Stage 1 and 250 ml. of glacial acetic acid were added and the mixture was subjected to boiling with reflux for 60 minutes. The reaction solution was reacted with 1.5 l. of a sodium salt solution. A precipitate was formed which was removed by suction and washed with methanol. The wet crude product was again formed into a slurry with 10% sodium salt solution and after removal by suction washed with methanol. The yield was 44 g.

Stage. 3.--Reduction of the nitro compound 44 g. of the nitro compound obtained in Stage 2 were added to a solution of 100 g. tin-II-chloride, 220 ml. concentrated hydrochloric acid and 330 ml. glacial acetic acid at 75 C. while stirring. After the completion of this step, the temperature was maintained at 95 C. for another 10 minutes. 600 ml. water were then added to the almost colorle'ss solution. The precipitate that formed was re- 6 moved by suction after cooling down of the solution and washed with a small amount of dilute hydrochloric acid. The yield was 25 g.

Stage 4.-Formation of the purple component A solution was prepared upon stirring from 10 g. of the amino compound obtained in Stage 3 in 36 ml. pyridine and 18 ml. dimethylformamide at a temperature of 35 C. 10 g. of the chloroformic a'cid cetylester were then added. The mass was subjected to further stirring for 30 minutes at 55 C. It was then poured into 200 ml. of a 10% sodium salt solution and the precipitate that was formed was removed by suction. The wet crude product was thereupon dissolved in 50 ml. methanol and precipitated with concentrated hydrochloric acid. The precipitate was removed by suction and washed with acetone. Yield: 10 g.

FORMATION OF A SOLUTION OF THE COUPLER 1 g. of the coupler compound thus obtained was suspended in 2 ml. methanol and reacted with dilute sodium hydroxide until neutral.

The solution was then incorporated in conventional manner in a halogen-silver emulsion and treated as described in Example 1.

Using 2-amino-S-diethylaminotoluene as the developer, a purple dye was obtained with an absorption maximum of 526 mp.

EXAMPLE 3 This example illustrates the purpose coupler of the formula is ai Stage 1.m-Pentadecylphenoxyethanol 46 g. of sodium were dissolved in 2.5 l. of abs. alcohol and added to 680 g. of m-pentadecylphenol (a product of the Aldrich Corporation of the United States of America) at 70 C. and while stirring. 161 g. of 2-chloroethanol were then added to the solution within a period of minutes. After keeping at boiling point for 2 hours, the solution was then cooled to 40 C. and the precipitated sodium chloride was removed by suction. The filtrate was cooled in the refrigerator and the desired product then precipitated. After removal by suction, the parent liquid was concentrated by evaporation to 1 liter solution. M.P; 51- 52 C.; total yield: 440 g.

Stage 2.--,8- (Pentade cylphenoxy) -ethylchloroformate This chloroformic acid ester was formed analogously to the manner in Stage 2 of Example 1. Instead of 460 g. of phenol, there were used 435 g. of the phenoxyethanol obtained in Stage 1 of the present example. The yield was 450 g.

Stage 3.-Making of the purple component 277.5 g. of 1 -(2',4',6' trichlor0phenyl)-3-( "-aminoanilino)-pyrazolone-(5) were dissolved in 1.5 l. pyridine and added in one batch at 40 C. to 330 g. of the chloroformic acid ester formed in Stage 2 while stirring. Subsequently, stirring was continued for another 30 minutes at 60 C., and the solution was then poured while stirring into a mixture of 61. of ice water and 2 1. of hydrochloric acid. The precipitate that formed was removed by suc- 7 8 tion and thoroughly washed with dilute hydrochloric acid trated hydrochloric acid and 1000 cc. ice water. The final and water. pH was 1 to 2.

The dried crude product was dissolved in 1.75 l. of .The formed precipitate was eliminated by suction and acetic acid ethyl ester and the solution was reacted with dried. It was dissolved hot in methanol for purification 2 l. of methanol. After 24 hours, suction was applied. MP. 5 and adjusted to a pH of 5 to 6 with a 20% sodium hydrox- 15 3-155 0.; yield: 400 g. ide solution. The precipitated coupler was removed by This purple coupler can be used as in Example 1. With suction, Washed with methanol and dried. M.P.: decompo- 2-amino-5-diethylaminotoluene it will furnish a color masition starting at 240 C. terial with an absorption maximum of 535 mg. The yellow colored coupler was incorporated in a green 10 sensitive negative emulsion. The emulsion was cast, dried E P 4 and photographically exposed. It was subjected to the negative color development process using N,N-diethyl-p- This example illustrates the making of a yellow colored phenylenediamine as devaloper and Potassium ferric) masking coupler of the formula 3.08 g. of p-anisidine in 37.5 ml. 2 N hydrochloric acid anide in the bleaching bath. A negative purple image was and 15 ml. water were diazotized at 0 C. with a solution obtained was an absorption maximum of 526 mp. of 1.73 g. of NaNO in 5 ml. water at a temperature of 0 Significant was smooth conversion coupling of the mask- C. The diazonium salt solution was then added at 0 C. ing couplers and the excellent stability of the mask in the to a solution of 18 g. of the purple component formed in bleaching bath.

Example 3 dissolved in 350 ml. pyridine. Stirring was con- We claim: tinned at room temperature for another 30 minutes and '1. A suspension or dispersion for incorporation in a phothe mass was subsequently poured while stirring into a tosensitive halogen-silver emulsion, the said suspension or mixture of 2 liters ice water and 500 m1. concentrated hydispersion comprising a carrier material having suspended drochloric acid. The formed precipitate was removed by or dispersed therein an acyl-amino-anilino-pyrazolone havsuction and washed with dilute hydrochloric acid and waing the formula ter. The dried crude product was recrystallized from H ligroine. M.P. 66-70 C.; yield: 18 g. NH O I R The component, an azo dye, had an absorption maxi- 40 mum of 425 mp. N

The yellow colored coupler, a so-called masking coupler, was incorporated in the form of a dispersion in a green sensitive negative emulsion. The emulsion was cast, dried and photographically exposed. Upon developing RI with a negative color developer (developer: N-ethyl-N- methane-sulfonamide-ethyl 3-methyl-4-aminoaniline-sulfate, a negative purple image was obtained, absorption wherein R is hydrogen, alkyl, halogen or an acid group; mam 533 m At the same time, there was left a positive R is alkyl, cycloalkyl, aryl, aryloxyalkyl or a substituted yellow image which therefore was opposed to the gradaalkyl, cycloalkyl, aryl or aryloxyalkyl group, wherein said tion of the purple image which yellow image could be substituent is halogen; R is hydrogen, halogen or a 803E used for masking the blue absorption of a purple color or COOH acid group or a phenylazo group; and wherein materiaL at least one of R and R is or includes an antidiflusion EXAMPLE 5 straight-chain or branched hydrocarbon group having from 8 to 20 carbon atoms. This example illustrates the making of another masking 2. The suspension or dispersion of claim 1, wherein coupler of the formula R is chlorine or a sulfonic acid group.

0 H 0OH CH 0 -NHNHC- N=NO(CHa)aS0 H 15 g. of 4-arnino-w-sulfopropyl-phenylether were dis- 3. The suspension or dispersion of claim 1, wherein R solved in 30 cc. concentrated hydrochloric acid and 50 cc. is alkyl having 8 to 20 carbon atoms.

water and diazotized at 05 C. with a solution of 5 g. 4. The suspension or dispersion of claim 1, wherein R of sodium nitrite and 25 cc. water. The diazonium salt is chlorophenyl, phenyl being further substituted by said solution was added in the course of half an hour to a so- 8 to 20 carbon hydrocarbon group.

lution of 35 g. of the purple coupler obtained in 'Example 5. The suspension or dispersion of claim 1, wherein R 3 and dissolved in 250 cc. pyridine. After stirring for 6 is alkylphenoxy, the phenyl group of phenoxy being furhours, the solution was precipitated in 225 cc. concenther substituted by said 8 to20 carbon hydrocarbon group.

6. The suspension or dispersion of claim 1 wherein R 11. The suspension or dispersion of claim 1, wherein is a phenylazo group of the following structure said pyrazolone 1s (5 O l= 6 0 R4 I If N=N CH:

| 01 01 $111 I 0 I0 I R, being alkyl or substituted alkyl, wherein said substitu- C1 ent is lower alkyl or a sulfo lower alkyl group. I

7. The suspension or dispersion of claim 6, wherein R is methyl.

8. The suspension or dispersion of claim 6, wherein R 12. The suspension or dispersion of claim 1, wherein is sulfo-propyl.

said pyrazolone is (HO-C1 13. The suspension or dispersion of claim 1 wherein the color coupler is O H Q-OCHaCHr-O -NHNH?J3N=N-O--(CH:)r-B OIH 9. The suspension or dispersion of claim 1, wherein References Cited 18 0 UNITED STATES PATENTS 2,983,608 5/1961 Beavers 96100 I 1$ g 3,127,269 3/ 1964 Greenhalgh et al 96-100 3,468,665 9/1969 Misu et a1. 96 -100 I FOREIGN PATENTS C1 1 1,044,778 10/1966 Great Britain 96-100 J. TRAVIS BROWN, Primary Examiner 1 1 us. 01. X.R. 10. The suspension or dispersion of claim 1, wherein 555 said pyrazolone is HaC O C (LNH 

